| 摘要 |
<p>PURPOSE:To prevent damage due to bending stress at the time of back washing by forming the inner wall surface of a plurality of holes provided through a planar body of porous material from one end surface thereof to the other, into a specific shape. CONSTITUTION:In case of treating exhaust gases of an Diesel engine, most of particulates in dust-laden gases are captured by the inner wall surface of a plurality of holes 55 of a filter element 51. Attachment and accumulation of the particulates on the inner wall surface of the hole 55 causes an increase in pressure drop of the gases, so that back washing is conducted by blowing off pressurized gases from ejector nozzles on the side of a gas outlet at proper intervals, wherein a considerably high pressure is produced in a passage of clean gases, exerting high pressure repeatedly to the outer wall surfaces 57 of the filter element 51 so as to crush the porous wall. However, because the inner wall surface of the hole 55 has a chevron-shape approaching the side wall 57, bending stress being generated is decreased.</p> |
